Cu-doped TiO2 nanopowders were prepared by sonochemical-assisted process via a precursor solution of titanium isopropoxide, copper nitrate trihydrate and sodium hydroxide in the presence of polyvinyl alcohol in combination with calcinations process. The as-synthesized products were calcined at various temperatures ranging from 500-1000°C. The physical microstructures, morphologies and chemical bonding of as-calcined nanopowders were characterized by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. It was noted that the crystallization, structure and size of the powders were strongly dependent on calcinations temperature. Their optical absorption properties were investigated and the results suggested that Cu dopant could significantly improve the optical absorption properties of TiO2.